The present invention relates to purification or sterilization of fluids, such as waste water, through ultraviolet light rays which are capable of killing or destroying unwanted microorganisms in fluids as is well-known. More specifically, the present invention relates to ultraviolet lamp systems which are immersed in the fluid to be purified. The systems may include a plurality of lamp modules each containing a plurality of lamp assemblies supported in parallel by and between spaced vertical legs forming a part of the module frame such as, for example, disclosed in U.S. Pat. No. 4,482,809 assigned by the inventor herein to the same assignee of the subject application. In the module device of this patent, the ultraviolet lamps are mounted to the legs of the frame by their surrounding protective sleeves whose opposite ends are open and mounted and sealed in sockets spaced along the legs. The lamps are powered through lead wires extending from an external control panel and received in both legs of the frame which are hollow for this purpose. The lead wires are connected to opposite ends of the lamps through contacts in the sockets; there being a separate pair of lead wires connected to each lamp at the opposite ends thereof respectively. The voltage and amperage of the lamps are controlled at a control panel located externally of the lamp modules.